Device for cooling the bearings of heated rolls

ABSTRACT

A cooling device for the bearings of overhung supported heated rolls. Such a device must shield the bearing against the thermal radiation of the heating device and the heated roll. A tube-like hollow body is mounted between the bearing and the heat source, that is, the heating device and heated roll. A drive shaft between the bearing on one side and the heated roll on the other is passed through the hollow body. The hollow body which the drive shaft passes through is completely sealed to contain the cooling fluid being passed or flown through the hollow body.

United States Patent [1 1 ,Segelken eta].

DEVICE FOR COOLING THE BEARINGS OF HEATED ROLLS Inventors: Rudolf Segelken, Muelheim;

Oskar Tippmann, Laemmerspiel; Peter Westebbe, Offenbach-Buergel,

all of Germany Assignee: Dienes-l loneywellGmhil,

Muelheim am Main, Germany Filed: Sept. 9, 1971 Appl. No.: 178,958

Foreign Application Priority Data Dec. 28, 1970 Germany P 70 47 913.9

us. Cl 165/47, 165/134, 308/77 Int. Cl. F24h 3/00 Field of Search 165/47, 134, 89,

[56] References Cited UNITED STATES PATENTS 2,352,206 6/1944 Kendall 165/47 Primary Examiner-Charles Sukalo Attorney-Lamont B. Koontz and Omund R. Dahle [57] ABSTRACT A cooling device for the bearings of overhung supported heated rolls. Such a device must shield the bearing against the thermal radiation of the heating device and the heated roll. A tube-like hollow body is mounted between the bearing and the heat source, that is, the heating device and heated roll. A drive shaft between the bearing on one side and the heated roll on the other is passed through the hollow body. The hollow body which the drive shaft passes through is completely sealed to contain the cooling fluid being passed or flown through the hollow body.

9 Claims, 2 Drawing Figures PATENTEflmcz 1 ms 'NVENTOR. RUDOLF SEGELKEN OSKAR TIPPMANN PETER WESTEBBE BY M5. M

A T TOR/VEX DEVICE FOR COOLING THE BEARINGS OF HEATED ROLLS The invention refers to cooling devices for bearings of overhung mounted heated rolls. If temperatures of more than 200 C are required at the outer surface of a heated roll, especially that bearing which is directed towards the roll is strongly heated by thermal radiation of the heating device and also by heat conduction along the supporting shaft of the roll. it is all the same, if the bearing is part of the roll-driving motor, or if a special bearing box carrying the driving shaft is located between the roll and the motor.

The invention deals with the problem to design an effective cooling device for the bearing. Such a device must shield the bearing against the thermal radiation of the heating device and the heated roll. This device must also prevent a transfer of heat to the bearing by thermal conduction.

This problem is solved by mounting a tube-like hollow body between the heat source (heated roll and heating device) and said bearing. A driving shaft between the bearing on one side and the heated roll on the other is passed through the hollow body made of such a material shielding against thermal radiation. The formed cavity, which the driving shaft passes through is completely sealed, so that a cooling fluid moved through will prevent heat conduction by the driving shaft. By this means any kind of heat transfer between the heat source and said bearing is interrupted. In a special type of the invention the driving shaft inside the cavity is in direct contact with the cooling fluid and the openings where the shaft passes through the walls of i the cavity are sealed by' shaft packings.

Fixed to said driving shaft is a centrifugal disk made of an excellent heat conducting material immersing into a cooling fluid. Said centrifugal disk constantly sprays cooling fluid against the inner wall of the cavity and on the other hand acts as a heat exchanger between the contacting driving shaft and the cooling fluid.

In another type of the invention the driving shaft is not in a direct contact with the cooling fluid but the hollow body is surrounding the shaft like a tube. Heat exchanging ribs are mounted so close to the shaft that they guarantee a good heat transfer although they don t contact the shaft.

Other types of the invention are characterized by the sub-claims. For a better understanding of the invention two types of the new cooling device are represented in the added drawings.

In both cases the heated roll 1 is fixed by its hub at the free end of the driving shaft 3. Said driving shaft is supported in a drive box 4 by means of two ball bearings 5. Only one of these bearings which is directed to the heated roll 1 is visible. Said driving shaft which is driven by an electro-motor is not shown in the drawing. Bearing box 4 is fixed to the machine mounting, for instance, at the draw-twisterrlnside the superficies of the heated roll 1 a stationary heating device 6, for instance, an inductive heater is mounted. This heating device is also fixed to the machine mounting and connected to a current source.

In order to protect bearing 5 againstover-heating an essentially truncated cone-like hollow body 7 is arranged between the heating source consisting of heated roll 1 and heating device 6 and the bearing, which is,

shielding bearing 5 against heat radiation. Hollow body 7 is traversed by-driving shaft 3. Said shaft in a cavity of the hollow body 7 is directly exposed to the passing cooling fluid, which is preferably water. On driving shaft 3 a centrigugal disk 8 made of an excellent heat conducting material is fixed, having a large contact area with the shaft. The cooling fluid enters into the hollow body 7 through a supply pipe 9 and leaves it through delivery pipe 10. The cooling fluid inside the truncated cone-like hollow body forms a sump of cooling fluid 11 in which a centrifugal disk 8 is immersing by its peripheral parts. When driving shaft 3 is rotating the centrifugal disk 8 immersing by its outer edge into the cooling fluid 11 permanently centrifuges fluid against the skewed inside wall 12 of the hollow body 7. Thereby the inside wall 12 is continuously covered by a film of cooling fluid which transfers the radiated heat exchanged with the cone-wall to the sump of the cooling fluid. This fluid is continuously exchanged by pipes 10 and 9. A suitable pumping and cooling device and in case, if necessary, a supply bin for the coolant are connected to line 9 and 10 of the cooling hollow body 7. Two circumferential sealings 13 are sealing the openings through which driving shaft 3 passes the bottom and the top wall of the truncated cone. As driving shaft 3 doesnt immerse into the fluid both sealings 13 must not be spray-proof. If the whole driving shaft should be surrounded by the cooling fluid circular sealings 13 must in addition be splash-proof. The centrifugal disk has two different functions. On one hand said disk is steadily generating a fluid film at the inner wall 12 of the hollow body 7 and on the other hand it serves as a heat conductor between driving shaft 3 and. the coolant 11 dissipating the heat from that part of the driving shaft which is inside the hollow body. By this means heat conducting from the heated roll 1 through its hub 2 and a driving shaft 3 to bearing 5 is interrupted. If necessary several centrifugal disks may be mounted to shaft 3. I

A second example of the new cooling device is shown by FIG. 2. Heated roll, driving shaft, heating device and hearing are represented in the same way as in FIG. '1. Here, too, the hollow body '17 is essentially truncated cone-shaped and 'forms a cavity 18 which is completely filled with coolant. The inner space of hollow body 17 is separated from the driving shaft 3 by a cylindrical wall 19 which carries ribs 20 for heat dissipation. Said cylindrical wall 19 surrounds the driving shaft 3 very closely but without contact. By this means the heat radiated from driving shaft 3 is absorbed by hollow body 17 because of an existing temperature drop between the shaft and the hollow body. In the same way as in example 1 the hollow body 17 is filled with the coolant which is preferably water, is shielding bearing .5 against heat radiation from heating device 6 and the heated roll 1. The fluid in cavity 18 of the hollow body 17 is-circulatingthrough feed-line 9 and outlet 10 and is continuously cooled.

With both examples the essentially truncated coneshaped cooling body 7, rasp l7, partially projects into the innerspace of heated roll 1 and the diameter of its base equals that of the heated roll. Hollow bodies with another'shape, e.g. cylindrical ones may be more practical if the construction of the heated roll and the heater is different.

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows:

1. Cooling device for bearings of overhung supported heated rolls, comprising a rotatable heated roll mounted on a drive shaft;

heating means for heating said heated roll;

a bearing for supporting said drive shaft;

a radiation shielding hollow body stationarily mounted between said bearing and said heated roll for impeding heat transfer from the heated roll to the bearing,

said drive shaft projecting through said hollow body and said hollow body having ports whereby cooling fluid is flown through said hollow body.

2. Cooling device according to claim 1, in which the drive shaft inside the hollow body is in direct contact to the cooling fluid and that at the inside of the cavity of said hollow body the openings for the drive shaft are sealed by shaft packings.

3. Cooling device according to claim 2, in which at that part of the drive shaft surrounded by the hollow body at least one centrifugal disk is mounted.

4. Cooling device according to claim 3, in which the centrifugal disk consisting of a good heat conducting material is mounted on the drive shaft having a large area of contact to the shaft.

5. Cooling device according to claim 4, in which the hollow body is partially filled by coolant, preferably by water, and that one segment of the centrifugal disk immerses into the sump of said coolant.

6. Cooling device according to claim 1, in which the hollow body tube-like surrounds the drive shaft.

7. Cooling device according to claim 6, in which at least the cylindrical inner wall which surrounds the drive shaft very closely, but without contact, is provided with ribs for the dissipation of heat.

8. Cooling device according to claim 1, characterized in that the hollow body has the shape of a truncated cone and that the diameter of its base is nearly equal to that of the heated roll.

9. Cooling device according to claim 1, characterized in that the hollow body at least partially projects into the interior space of heated roll.

* I i I! 

1. Cooling device for bearings of overhung supported heated rolls, comprising a rotatable heated roll mounted on a drive shaft; heating means for heating said heated roll; a bearing for supporting said drive shaft; a radiation shielding hollow body stationarily mounted between said bearing and said heated roll for impeding heat transfer from the heated roll to the bearing, said drive shaft projecting through said hollow body and said hollow body having ports whereby cooling fluid is flown through said hollow body.
 2. Cooling device according to claim 1, in which the drive shaft inside the hollow body is in direct contact to the cooling fluid and that at the inside of the cavity of said hollow body the openings for the drive shaft are sealed by shaft packings.
 3. Cooling device according to claim 2, in which at that part of the drive shaft surrounded by the hollow body at least one centrifugal disk is mounted.
 4. Cooling device according to claim 3, in which the centrifugal disk consisting of a good heat conducting material is mounted on the drive shaft having a large area of contact to the shaft.
 5. Cooling device according to claim 4, in which the hollow body is partially filled by coolant, preferably by water, and that one segment of the centrifugal disk immerses into the sump of said coolant.
 6. Cooling device according to claim 1, in which the hollow body tube-like surrounds the drive shaft.
 7. Cooling device according to claim 6, in which at least the cylindrical inner wall which surrounds the drive shaft very closely, but without contact, is provided with ribs for the dissipation of heat.
 8. Cooling device according to claim 1, characterized in that the hollow body has the shape of a truncated cone and that the diameter of its base is nearly equal to that of the heated roll.
 9. Cooling device according to claim 1, characterized in that the hollow body at least partially projects into the interior space of heated roll. 